Rabbits Of Ages Research Articles

Efficacy of antiparasitic macrocyclic lactone drops against passalurosis and psoroptic mange in rabbits

The purpose of the research is to study the efficacy of a macrocyclic lactone drug using the spot-on method against passalurosis and psoroptic mange in rabbits.Materials and methods. The study was conducted at the Department of Parasitology and Veterinary-Sanitary Expertise of the MVA named after K. I. Skryabin in 2022–2023 to determine the efficacy of antiparasitic drops (active ingredients: phenylpyrazole derivative, pyrazinoisoquinoline derivative, macrocyclic lactone, insect growth regulator, manufactured by AVZ S-P, LLC) against passalurosis and psoroptic mange. The antiparasitic drops were applied by the spot-on method to rabbits of different age and sex groups in doses of 0.5 mL per animal for body weight of up to 4 kg and 1 mL per animal for body weight of 4 to 8 kg against passalurosis and psoroptic mange. Rabbit fecal samples were examined using the Fülleborn method. Skin scrapings from the inner auricle surface were studied for Psoroptes cuniculi mites as per D. A. Priselkova.Results and discussion. The antiparasitic drug was found to have 100 % efficacy against ticks Psoroptes cuniculi and nematodes Passalurus ambigus.

Infections of reproductive organs in female rabbits

Symptomatic infertility is a temporary or permanent disturbance in reproductive function wherein the animal cannot become pregnant due to diseases of genital organs or systemic diseases. Since female rabbits, due to their precociousness and fertility, are often used for reproduction, the leading causes of symptomatic infertility in them are the absence of estrous cycles or their deficiency and inflammation of tissues of the reproductive system. Infertility is observed in female rabbits developing such infectious diseases as pasteurellosis, spirochetosis, and myxomatosis. It is due to these diseases that obstetric and gynecological pathology (vulvitis, vulvovaginitis, metritis, pyometra, mastitis), long-term infertility, and death of animals are recorded most often. External genitalia (vulva) and mammary glands are the main routes of infection in female rabbits. The most common microorganisms causing inflammatory processes in reproductive organs are non-specific, such as Staphylococcus and Pasteurella, and specific microbes, such as toxoplasma. Spirochetes, Listeria, and Salmonella are much less common. It has been found that on farms of different forms of ownership in the Dnipropetrovsk region, the most common infectious diseases in rabbits are myxomatosis (20 %), viral hemorrhagic disease (13 %), eimeriosis (30 %), pasarulosis (10 %), and spirochetosis (10 %). Inflammation of genital tissues, especially inflammatory processes in the uterus, is the most common disease in female rabbits. The general frequency of uterine diseases increases with age, reaching more than 50% in aged female rabbits. Endometritis was the most frequent inflammatory process diagnosed in 10 % of cases and was potentially purulent, catarrhal, lymphoplasmacytic, or enterohemorrhagic. Metritis was observed in 5 % of cases and pyometra in 3 %. Autopsy of forcibly slaughtered or dead animals revealed such uterine diseases as hydrometer and mucometer. Hydrometers and mucometers comprised 8 % of uterine diseases, and the average age of sick female rabbits was 3 years. The etiology remains unclear but is potentially related to endometrial hyperplasia or endometritis. However, in some cases, no underlying uterine disease was found. During acute infection of the organs of the reproductive system of female rabbits, a serous mucocatarrhal or mucopurulent exudate is released from the genital slit. Chronic inflammatory processes of the genital organs often occur without signs of disease or are manifested by decreased fertility or abortion.

Advanced maternal age leads to changes within the insulin/IGF system and lipid metabolism in the reproductive tract and preimplantation embryo: insights from the rabbit model.

Reproductive potential in women declines with age. The impact of ageing on embryo-maternal interactions is still unclear. Rabbits were used as a reproductive model to investigate maternal age-related alterations in reproductive organs and embryos on Day 6 of pregnancy. Blood, ovaries, endometrium, and blastocysts from young (16-20 weeks) and advanced maternal age phase (>108 weeks, old) rabbits were analysed at the mRNA and protein levels to investigate the insulin-like growth factor (IGF) system, lipid metabolism, and stress defence system. Older rabbits had lower numbers of embryos at Day 6 of pregnancy. Plasma insulin and IGF levels were reduced, which was accompanied by paracrine regulation of IGFs and their receptors in ovaries and endometrium. Embryos adapted to hormonal changes as indicated by reduced embryonic IGF1 and 2 levels. Aged reproductive organs increased energy generation from the degradation of fatty acids, leading to higher oxidative stress. Stress markers, including catalase, superoxide dismutase 2, and receptor for advanced glycation end products were elevated in ovaries and endometrium from aged rabbits. Embryonic fatty acid uptake and β-oxidation were increased in both embryonic compartments (embryoblast and trophoblast) in old rabbits, associated with minor changes in the oxidative and glycative stress defence systems. In summary, the insulin/IGF system, lipid metabolism, and stress defence were dysregulated in reproductive tissues of older rabbits, which is consistent with changes in embryonic metabolism and stress defence. These data highlight the crucial influence of maternal age on uterine adaptability and embryo development.

Myofibroblast senescence promotes arrhythmogenic remodeling in the aged infarcted rabbit heart.

Progressive tissue remodeling after myocardial infarction (MI) promotes cardiac arrhythmias. This process is well studied in young animals, but little is known about pro-arrhythmic changes in aged animals. Senescent cells accumulate with age and accelerate age-associated diseases. Senescent cells interfere with cardiac function and outcome post-MI with age, but studies have not been performed in larger animals, and the mechanisms are unknown. Specifically, age-associated changes in timecourse of senescence and related changes in inflammation and fibrosis are not well understood. Additionally, the cellular and systemic role of senescence and its inflammatory milieu in influencing arrhythmogenesis with age is not clear, particularly in large animal models with cardiac electrophysiology more similar to humans than previously studied animal models. Here, we investigated the role of senescence in regulating inflammation, fibrosis, and arrhythmogenesis in young and aged infarcted rabbits. Aged rabbits exhibited increased peri-procedural mortality and arrhythmogenic electrophysiological remodeling at the infarct border zone (IBZ) compared to young rabbits. Studies of the aged infarct zone revealed persistent myofibroblast senescence and increased inflammatory signaling over a 12-week timecourse. Senescent IBZ myofibroblasts in aged rabbits appear to be coupled to myocytes, and our computational modeling showed that senescent myofibroblast-cardiomyocyte coupling prolongs action potential duration (APD) and facilitates conduction block permissive of arrhythmias. Aged infarcted human ventricles show levels of senescence consistent with aged rabbits, and senescent myofibroblasts also couple to IBZ myocytes. Our findings suggest that therapeutic interventions targeting senescent cells may mitigate arrhythmias post-MI with age.

Епізоотологічні особливості геморагічної хвороби кролів, викликаної вірусами першого (GI.[1) та другого (GI.[2) типів в Україні у 2021 – 2022 рр.

Goal. To determine the epizootological features of rabbit hemorrhagic disease (RHD) caused by viruses of the first and the second types in Ukraine in 2021–2022. Methods. The work was performed based on 28 rabbit farms from 10 regions of Ukraine and in the laboratory of the Institute of Veterinary Medicine of NAAS. Epizootological, clinical, pathomorphological, molecular-genetic, immunochromatographic, bacteriological, and statistical research methods were used. Results. It was established that the form of manifestation of the epizootic process in RHD in 2021–2022 were outbreaks of the disease registered in 10 regions: in 17 farms it was caused by a virus of the first type (English — RHDV (GI. 1)), and in 11 farms — by a virus of the second type (English — RHDV2 (GI. 2)). The indicator of the adversity of Ukraine with RHD caused by both types of viruses was 40% in 2021, and 28% in 2022. Based on the study of indicators of the epizootic process, such as the damage and death of rabbits of a certain age (technological) groups, the significance of morbidity, mortality, and lethality, the course of the disease in rabbits of different age groups, as well as the seasonality of its outbreaks, the features were determined of the course of hemorrhagic disease caused by RHDV2 (GI. 2), compared to the “classical” RHDV (GI. 1). The obtained results indica­ted a lower virulence of RHDV2 (GI. 2) circulating in Ukraine compared to the “classic” strain of the virus. However, the established features of the seasonal manifestation of RHD outbreaks, taking into account the short observation period, require further research. Conclusions. In 2021–2022, RHD epizootic outbreaks caused by RHDV (GI. 1) occurred more often in Ukraine, and the country’s vulnerability to this disease was 36%. The second type of virus (GI. 2) was less common, with a prevalence of 16%. RHDV2 (GI. 2) circulated mainly in the central and northern regions, and RHDV (GI. 1) was distributed throughout the country. In general, the epizootic process caused by the virus RHDV2 (GI. 2) had many differences from the process caused by RHDV (GI. 1).

Effect of Tissue Composition and Microstructure on Rabbit Meat Optical Properties.

To facilitate the design of an optical detection system for assessing rabbit meat quality, nine rabbits of different ages, weights, and varieties were used to collect optical coefficients, compositions, and microstructures from external oblique muscle (EOM) and internal oblique muscle (IOM) samples to research the relationship between them. The results show that rabbit age had a significant influence (P < 0.05) on the absorption coefficient (μa) and the proportion of myoglobin in IOM and EOM, and the older the rabbits are, the greater the μa and the proportion of myoglobin are. Weight also significantly (P < 0.05) influenced the muscle fiber cross-sectional area. The age and weight had a significant (P < 0.05) impact on the reduced scattering coefficient (μs'). The linear fitting results between the relative proportion of myoglobin and the μa showed that the higher the myoglobin content is, the greater the μa is. The linear fitting results between the cross-sectional area of muscle fiber and the μs' showed that the smaller the cross-sectional area of muscle fiber is, the greater the μs' is. These results will be helpful to intuitively understand the working principle of spectral technology in meat quality detection.

Ultrastructural study for the gonadotrophs and somatotrophs of the pituitary gland in aging rabbits of local bread (oryctolagus cuniculus)

Eighteen rabbit of local bread were classified into3 groups A, B, and C&#x0D; Group A were 6 rabbits of age one year&#x0D; Group B were 6 rabbits of age three year&#x0D; Group C were 6 rabbits of age five year&#x0D; The whole animals were accomidated for one month before the study, after that the whole animals were exposed to intensive dose of chloroform and then scarified to obtain the pituitary gland by doing anatomical technique EM processing technique. was done and finally the pituitary gland were examined at the anterior lobe ( pars distalis ) to demonstrate the somatotrophes and gonadotrophes ( FSH and LH ) secreting cells .&#x0D; The present study revealed that somatotrophes and gonado trophes were containing spherical and oval nuclei at one year of age with presence of abundant secretary granules in its cytoplasm associated with Golgi apparatus, these structures were decreased in number and size proportionally with increase of the age of animal at 3 and 5 years .

Clinical and Anatomical Changes induced by Sciatic Nerve Section of Weaning Age Rabbits

The aim of the study was to explore the clinical and anatomicalchanges occured after Sciatic nerve section in the weaning age in rabbits.Twenty-five rabbits were used in this study ranging from 1-2.5 months.Divided into five subgroups according to the number of survival days(W7) (W14) (W30) (W60) (W90). Surgery was performed under generalanesthesia. The nerve was sectioned using a small surgical scissor.Clinicalay few days later, the sign of right hind paws paralysis wasobserved clearly. The results revealed of a gap formation between thetwo nerve stumps [proximal and distal], and the gap increases on the dayfourteenth.During the following two weeks, ulcers began to appear in the skin at thedorsal side of the ankle joint, and there was also an enlarged popliteallymph node. Within 30-60 days another area was invaded by ulcer withor without bone exposure, the anterior part of the posterior side of thehind limb. After 90 days, there was severe ulceration and bone exposurewith enlarged lymph nodes and the ulceration extended to the ventralside of the hindlimb. Results showed a gradual worsening of thecondition and without improvement in peripheral nerves.&#x0D;

Consequences and Mechanisms of Left Atrium Remodeling in Aging Rabbits.

To investigate the consequences and mechanisms of myocardium remodeling of aging left atrium, we analyzed the main cardiac electrophysiological parameters such as rest membrane potential, action potential amplitude, maximum rate of action potential increase (max dV/dt), action potential plateau, and 30, 50, and 90% action potential duration (APD30, APD50, and APD90, respectively), as well as the inducibility and duration of atrial arrhythmias in adult and aging rabbits. L-type calcium current was also recorded. The collagen content in the myocardium and ultrastructure of left atrial cells were also studied. Significant changes were detected in the electrophysiological parameters and structure in aged left atrium, which can contribute to atrial susceptibility to arrhythmia in aged rabbits.

Proteomic analysis reveals that aging rabbit vocal folds are more vulnerable to changes caused by systemic dehydration

BackgroundOlder adults are more prone to develop systemic dehydration. Systemic dehydration has implications for vocal fold biology by affecting gene and protein expression. The objective of this study was to quantify vocal fold protein changes between two age groups and hydration status, and to investigate the interaction of age and hydration status on protein expression, which has not been investigated in the context of vocal folds before. Comparative proteomics was used to analyze the vocal fold proteome of 6.5-month-old and > 3-year-old rabbits subjected to water ad libitum or water volume restriction protocol.ResultsYoung and older adult rabbits (n = 22) were either euhydrated (water ad libitum) or dehydrated by water volume restriction. Dehydration was confirmed by body weight loss of − 5.4% and − 4.6% in young and older groups, respectively, and a 1.7-fold increase of kidney renin gene expression in the young rabbits. LC-MS/MS identified 2286 proteins in the rabbit vocal folds of young and older adult rabbits combined. Of these, 177, 169, and 81 proteins were significantly (p ≤ 0.05) affected by age, hydration status, or the interaction of both factors, respectively. Analysis of the interaction effect revealed 32 proteins with opposite change patterns after dehydration between older and young rabbit vocal folds, while 31 proteins were differentially regulated only in the older adult rabbits and ten only in the young rabbits in response to systemic dehydration. The magnitude of changes for either up or downregulated proteins was higher in the older rabbits. These proteins are predominantly related to structural components of the extracellular matrix and muscle layer, suggesting a disturbance in the viscoelastic properties of aging vocal fold tissue, especially when subjected to systemic dehydration.ConclusionsWater restriction is a laboratory protocol to assess systemic dehydration-related changes in the vocal fold tissue that is translatable to human subjects. Our findings showed a higher number of proteins differentially regulated with a greater magnitude of change in the vocal folds of older adult rabbits in the presence of systemic dehydration compared to younger rabbits. The association of these proteins with vocal fold structure and biomechanical properties suggests that older human subjects may be more vulnerable to the effects of systemic dehydration on vocal function. The clinical implications of these protein changes warrant more investigation, but age should be taken into consideration when evaluating vocal treatment recommendations that interfere with body fluid balance.

PREVALENSI Eimeria spp. PADA TERNAK KELINCI

This study was aimed to determine the prevalence of Eimeria spp., to determine the differences in the prevalence of Eimeria spp. in rabbits of various ages and to know the species of Eimeria spp. which infect rabbits of various ages in Cilongok District, Banyumas Regency. The main objects of observation were weaning rabbits (1-5 weeks), weaning (6-24 weeks) and adults (24 weeks). The research method used is survey method with purposive sampling technique. The data were analyzed using the method of description and chi square. The sample used was rabbit feces as much as 5 grams per head with a sample of 96 rabbits in three age periods each totaling 32 rabbits. The results of the analysis showed that the prevalence of Eimeria spp. in rabbits the weaning period was 96.88%, after weaning was 96.88% and adults were 78.13%, and the prevalence of Eimeria spp. overall by 90.62%. The species Eimeria spp. that infect rabbits are Eimeria exigua, Eimeria perforans, Eimeria piriformis, Eimeria flavescens, Eimeria stiedai, Eimeria intestinalis, Eimeria media, Eimeria coecicola and Eimeria magna. P0.05 indicates that there is a difference in the prevalence of Eimeria spp. in rabbits of various ages in Cilongok District, Banyumas Regency. Prevalence of Eimeria spp. very significant effect on weaning, weaning and adult rabbits.

Методика исследования вибрационной активности голосовых связок

In order to develop equipment for diagnosing the state of the human vocal folds (VF) and monitoring their activity during treatment, a complex of studies of animal VF samples (rabbits) was performed. A highly sensitive non-contact laser-optical equipment and a technique for recording VF vibrations in an air flow with controlled pressure have been developed. For a group of rabbits of the same age, data are given on the registration of vibrational frequencies in healthy VFs and received as a result of therapeutic effects ("treated" VFs). It was found that when air is passed through the trachea under a slight pressure of 10-20 mm Hg. three peaks of the characteristic frequencies of natural mechanical vibrations of the VF appear in the range of ~ 200 - 1000 Hz. As a rule, this is the fundamental frequency f1 and its two harmonics f2 = 2 f1 and f3 = 3 f1. Best of all, these oscillations are excited at the end of the outflow of air under a pressure of 1 - 5 mm Hg. A difference was found in the excited vibrations at low frequencies in healthy VF and VF with defects in the form of a scar on one ligament. The frequencies of the lowest natural vibrations in a defective VF are somewhat higher compared to the lowest frequency in a healthy VF, which is explained by an increase in its rigidity during the formation of scar tissue. The technique is characterized by ease of registration, sensitivity and informativeness during treatment by methods of regenerative medicine. Diagnosis of the state of the VF during treatment in comparison with the data for a healthy VF seems to be informative and useful for restoring the vibrational properties of the vocal cords during the treatment.

Quantitative proteomics to study aging in rabbit spleen tissues.

Aging is a process that occurs in tissues and across species, leading to the degradation of many biological processes. We previously demonstrated that rabbits are a feasible model for studying aging due to their genetic homology and relatively short lifespan in comparison to humans. We utilized a cPILOT multiplexing strategy to identify proteomic changes in spleen tissues of young, middle, and old aged rabbits. We identified 63 proteins that change significantly (p<0.05) with age and notably these proteins relate to nucleotide and RNA binding, DNA repair, actin regulation, and immune system pathways. Here, we explore the implications of aging in the spleen and demonstrate the utility of a rabbit model to understand aging processes.

Penile Girth Enhancement Using Amniotic Membrane in a Rabbit Model: A stereological study.

This study aimed to evaluate the efficacy of penile girth enhancement (PGE) using amniotic membrane (AM) as a graft in a rabbit model. Additionally, quantitative histological data of the structure of the penis were obtained by stereological studies. This study was conducted at the Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. In this study, 20 adult male rabbits of similar age and weight were allocated to two groups: sham surgery and surgery+AM. Both groups underwent surgery in which a longitudinal I-shaped midline incision was made in the tunica albuginea on the dorsal surface of the penis. The surgery+AM group underwent PGE using AM as a graft. The penile length and mid circumference were measured using a vernier caliper before and two months after the surgery. The mean total volume and diameter of the penis significantly increased in the surgery+AM group (P <0.03 and P <0.04, respectively). On stereological evaluation, a significant increase in the mean volumes of the tunica albuginea and corpora cavernosa was observed in the surgery+AM group compared to the sham group (P <0.01 and P <0.03, respectively). Additionally, the mean volume densities of the collagen bundles, muscle fibres, cavernous sinuses, and the total number of fibroblasts and smooth muscle cells increased in the surgery+AM group compared to the sham group (P <0.05 each). No infections, bleeding or other complications were observed. The use of AM as a graft is a method that shows promising results for material use in penile enhancement. Thus, it may be considered for PGE in the future.

Influence of olfactomy, photoperiodic factor and physical activity on the dynamics of circadian rhythm of blood glucose in rabbits

In our study, we analyzed changes in blood glycemic reactions in 30-, 90-, 180-, and 365-day-old rabbits under the influence of physical activity and interceptive stimulation. As a result of the activation of nervous, hormonal, and enzymatic regulatory mechanisms during short-term physical exercise, anabolic reactions of glucose metabolism in the body, regardless of age, are enhanced due to glycogen resources and an additional supply of glucose in the blood. Long-term, but also heavy, physical activity, on the contrary, enhances the catabolic side of glucose metabolism in the body and leads to a decrease in blood glucose levels. In our study, the determination of blood glucose levels in experimental rabbits of different ages was carried out after interoceptive stimulation, in particular, irritation of rectal mechanoreceptors with pressure 80-100 mm Hg. Based on these experimental facts, one can conclude that the mechanisms of interoceptive regulation, especially the central nervous and neuroendocrine mechanisms regulating the homeostatic state of the internal environment, are not fully formed yet in young animals and do not have a long-term effect on the level of glucose in the blood. Based on these experimental facts, it can be concluded that the mechanisms of interoceptive regulation, especially the central nervous and neuroendocrine mechanisms regulating the homeostatic state of the internal environment, have not been fully formed yet in young animals and do not have a long-term effect on the level of glucose in the blood. This can also be explained by the fact that the dynamic and rhythmic nature of blood glycemic reactions in young animals is not so pronounced. However, in older animals, these reactions, while maintaining their high dynamic and rhythmic properties, develop in the form of static hyperglycemia.

Endoparasites of rabbits (Oryctolagus cuniculus domesticus) in Southern Ukraine

One of the main tasks of ecological parasitology at the present stage is to establish patterns of spread of invasive diseases of animals in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Among the many pathogens, endoparasites play a major role in a number of diseases in rabbits with increased morbidity and mortality. In the body of both wild and domestic rabbits several species of parasites that form a parasitocenosis can be localized. The latter have a pathogenic effect on organs and tissues, leading to reduced weight gain, premature slaughter and even mortality. The prevalence of endoparasitoses was studied in weaned rabbits 60 days of age, 120 days of age at fattening, 180 days of age – mating age and adults of 320 days of age to determine the extensiveness and intensity of the dominant invasion. A total of 720 head was studied, 180 animals from each age group. Three species of nematodes were recorded in the rabbits: Trichostrongylus retortaeformis (Zeder, 1800), Nematodirus leporis (Ransom, 1907) and Passalurus ambiguus (Rudolphi, 1819); the cestode Taenia pisiformis (Bloch, 1780); three species of Emeria: Eimeria stiedae (Lindermann, 1865), which parasitizes in the bile ducts of the liver and gallbladder, E. magna (Perard, 1925) and E. media (Kessel, 1929) – in the epithelial cells of the intestine. The prevalence of the infestation depends on the age of the animals. According to the data obtained, eimeriosis was one of the main parasitic diseases of the rabbits. Dominant invasions of Eimeria in the intestines of 60-day-old rabbits were found in the studied animals, their extensiveness reached 19.4%, while the spread of hepatic Eimeria was registered in 13.3% of the examined rabbits. The total infestation of weaned rabbits with helminths was 22.2%, in rabbits for fattening – 26.7%, and in rabbits of mating age and adults – 20.0% and 20.6%, respectively. Global climate change will change the distribution and dynamics of soil-borne helminthiases, but host immunity may also affect host-parasite interactions. Subsequent studies will be aimed at elucidating the effect of mono and mixed invasions on the body of rabbits. Updated data on helminthiasis will expand the screening strategy to maintain rabbit health and reduce economic losses.

Propagation and phenotypic analysis of mutant rabbits with MSTN homozygous mutation

Myostatin gene (MSTN) encodes a negative regulator for controlling skeletal muscle growth in animals. In this study, MSTN-/- homozygous mutants with "double muscle" phenotypic traits and stable inheritance were bred on the basis of MSTN gene editing rabbits, with the aim to establish a method for breeding homozygous progeny from primary MSTN biallelic mutant rabbits. MSTN-/- primary mutant rabbits were generated by CRISPR/Cas9 gene editing technology. The primary mutant rabbits were mated with wild type rabbits to produce F1 rabbits, whereas the F2 generation homozygous rabbits were bred by half-sibling mating or backcrossing with F1 generation rabbits of the same mutant strain. Sequence analysis of PCR products and its T vector cloning were used to screen homozygous rabbits. The MSTN mutant rabbits with 14-19 week-old were weighed and the difference of gluteus maximus tissue sections and muscle fiber cross-sectional area were calculated and analyzed. Five primary rabbits with MSTN gene mutation were obtained, among which three were used for homozygous breeding. A total of 15 homozygous rabbits (5 types of mutants) were obtained (M2-a: 3; M2-b: 2; M3-a: 2; M7-a: 6; M7-b: 2). The body weight of MSTN-/- homozygous mutant rabbits aged 14-19 weeks were significantly higher than that of MSTN+/+ wild-type rabbits of the same age ((2 718±120) g vs. (1 969±53) g, P < 0.01, a 38.0% increase). The mean cross sections of gluteus maximus muscle fiber in homozygous mutant rabbits were not only significantly higher than that of wild type rabbits ((3 512.2±439.2) μm2 vs. (1 274.8±327.3) μm2, P < 0.01), but also significantly higher than that of MSTN+/- hemizygous rabbits ((3 512.2±439.2) μm2 vs. (2 610.4±604.4) μm2, P < 0.05). In summary, five homozygous mutants rabbits of MSTN-/- gene were successfully bred, which showed a clear lean phenotype. The results showed that the primary breeds were non-chimeric mutant rabbits, and the mutant traits could be inherited from the offspring. MSTN-/- homozygous mutant rabbits of F2 generation could be obtained from F1 hemizygous rabbits by inbreeding or backcrossing. The progenies of the primary biallelic mutant rabbits were separated into two single-allelic mutants, both of which showed a "double-muscle" phenotype. Thus, this study has made progress in breeding high-quality livestock breeds with gene editing technology.

PD31-05 REPEATED TRANSURETHRAL INTERVENTIONS INCREASE ELASTIN DEGRADATION AND STRICTURE SEVERITY

You have accessJournal of UrologyCME1 May 2022PD31-05 REPEATED TRANSURETHRAL INTERVENTIONS INCREASE ELASTIN DEGRADATION AND STRICTURE SEVERITY Michael Witthaus, Jathin Bandari, Thomas Will Fuller, Valmik Bhargava, Jill Buckley, and Mahadevan Rajasekaran Michael WitthausMichael Witthaus More articles by this author , Jathin BandariJathin Bandari More articles by this author , Thomas Will FullerThomas Will Fuller More articles by this author , Valmik BhargavaValmik Bhargava More articles by this author , Jill BuckleyJill Buckley More articles by this author , and Mahadevan RajasekaranMahadevan Rajasekaran More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002582.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Repeated transurethral interventions can cause or exacerbate urethral stricture disease by increasing tissue damage. A clear understanding of molecular mechanisms involved in increased fibrogenesis would enable development of optimal strategies to minimize progression or prevent stricture recurrence. Recently elastin, an extracellular matrix protein has been implicated in heart, liver and kidney fibrosis. We hypothesize repeated transurethral mechanical stretch accelerates elastin degradation and increases stricture severity. METHODS: Electrocautery was used to induce strictures in middle aged rabbits (12 months; n=6; Fig A). Rabbits (n=3) that showed evidence of stricture development at 14 days post-injury were further subjected to urethral wall stretch using a Foley catheter (balloon inflated to 14 mm diameter for 10 minutes, once a week for 4 weeks; Fig B). Animals were then allowed to recover and subjected to retrograde urethrogram (RUG) to confirm stricture progression and sacrificed at 45 days post-injury. Urethral tissues were harvested and subjected to immunostaining (Verhoeff–Van Gieson; VVG) for elastin. Results were then validated in human urethral scar tissues (n=3) obtained from patients undergoing urethroplasty. RESULTS: RUG findings are summarized in the Fig C. The RUGs performed showed a significant increase in stricture severity after balloon dilation (Fig C -bottom panel). The methodology utilized in the animal model was confirmed fluoroscopically to be replicable. VVG showed strong labeling for elastin (Fig E-F; black stain; yellow arrows) in rabbit and human (Fig G) scar tissues relative to controls (Fig D). CONCLUSIONS: Our findings confirm that this approach is a viable model to study transurethral intervention induced fibrogenesis. It further supports our hypothesis that urethral wall stretch worsens stricture severity due to elastin degradation. This may be an initiating factor in tissue remodeling after injury. Targeting elastin using an elastase may be a potential pharmacological intervention to treat or prevent stricture recurrence after transurethral interventions. Source of Funding: UCSD Academic Senate © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e542 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Michael Witthaus More articles by this author Jathin Bandari More articles by this author Thomas Will Fuller More articles by this author Valmik Bhargava More articles by this author Jill Buckley More articles by this author Mahadevan Rajasekaran More articles by this author Expand All Advertisement PDF DownloadLoading ...

Cross-protection, infection and case fatality rates in wild European rabbits experimentally challenged with different rabbit haemorrhagic disease viruses.

Rabbit haemorrhagic disease virus 2 (RHDV2) is now the dominant calicivirus circulating in wild rabbit populations in Australia. This study compared the infection and case fatality rates of RHDV2 and two RHDVs in wild rabbits, as well as their ability to overcome immunity to the respective other strains. Wild rabbits were allocated to groups either blindly or based on pre-screening for RHDV/RHDV2 antibodies at capture. Rabbits were monitored regularly until their death or humane killing at 7 days post infection. Liver and eyeball samples were collected for lagovirus testing and aging rabbits, respectively. At capture, rabbits showed high seroprevalence to RHDV2 but not to RHDV. In RHDV/RHDV2 seronegative rabbits at capture, infection rates were highest in those inoculated with RHDV2 (81.8%, 18 out of 22), followed by K5 (53.8%, seven out of 13) and CZECH (40.0%, two out of five), but these differences were not statistically significant. In rabbits with previous exposure to RHDV2 at capture, infection rates were highest when inoculated with K5 (59.6%, 31 out of 52) followed by CZECH (46.0%, 23 out of 50), with infection rates higher in younger rabbits for both viruses. In RHDV/RHDV2 seronegative rabbits at capture, case fatality rates were highest for those inoculated with K5 (71.4%), followed by RHDV2 (50.0%) and CZECH (50.0%). In rabbits with previous exposure to RHDV2 at capture, case fatality rates were highest in rabbits inoculated with K5 (12.9%) followed by CZECH (8.7%), with no case fatalities following RHDV2 inoculation. Case fatality rates did not differ significantly between inoculums in either serostatus group at capture. Based on multivariable modelling, time to death post RHDV inoculation increased in rabbits with recent RHDV2 exposure compared with seronegative rabbits and with age. The results suggest that RHDV2 may cause higher mortalities than other variants in seronegative rabbit populations but that K5 may be more effective in reducing rabbit populations in an RHDV2-dominant landscape.

Prospective survey of neoplastic and non-neoplastic uterine disorders in 116 domestic rabbits (Oryctolagus cuniculus)

Earlier studies indicate that the risk for uterine tumours in rabbits may be as high as 60–80%. This high occurrence and the need for routine neutering of non-breeding pet rabbits have recently been in the spotlight. This study aimed to describe and compare macroscopic and histopathological alterations in uteri collected from domestic rabbits of various ages that were neutered, deceased, or euthanized without a suspected uterine disorder (NoUD; n = 94) and from rabbits with a suspected uterine disorder (UD; n = 22). In the NoUD group, uteri of 41 rabbits (44%) displayed histopathological findings and 12 rabbits (13%) had neoplasms. Samples from thirteen rabbits (14%) evinced histopathological findings with no macroscopic alterations. The most frequent diagnoses were cystic endometrial hyperplasia (26% of the 41 uteri), adenocarcinoma (9%), and polyps (5%). In the UD group, uteri from 21 (95%) out of 22 rabbits exhibited pathological alterations; in 2 (10%) of these, the changes (cystic endometrial hyperplasias) were seen only in histology. The most frequent diagnoses in the uteri of the UD group were cystic endometrial hyperplasia (77%) and adenocarcinoma (54%). Uterine malignant neoplasia affected 40% of all rabbits aged over 3 years, and the odds of a malignant uterine tumour in these rabbits were approximately 19-fold higher than in rabbits aged under 3 years. Uterine disorders are common in domestic rabbits, even without a suspected uterine disease, and the risk of uterine neoplasia markedly increases after 3 years of age. A macroscopically normal uterus may have pathological changes and ovariohysterectomy should be therefore preferred over ovariectomy at least in older rabbits.